A Classroom Challenge: Laptop with a Dead Battery
Is there a simple remedy?
Customers tell us some classrooms see as many as six students arrive daily with dead batteries in their laptops.
What if the laptop is necessary for a lesson or a test? What do other students do when their leader exits to find extension cords or power strips? This problem confounds both secondary and post-secondary institutions.
This issue is so problematic that one well-endowed university facilities manager told us their policy is avoidance. They will not provide extra outlets in lecture halls. They put the responsibility on students rather than committing to 120V outlets at every seat in every classroom.
The Pandemic hindered learning. Do students and instructors need this frustration too?
Think Batteries
Since 2019, all laptops sold can charge using a USB-C connection. This connection type has already spread to many other devices. It is already a European standard for charging a phone. All that is necessary is to provide a battery solution in the classroom.
This sounds easy.
Why do Student Laptops run out of power?
The obvious reason is that they do not arrive at school with fully charged laptops. Many schools appeal to parents for their assistance in this matter but it only takes a few to create a class disruption.
The not-so-obvious reason relates to the inadequacy of the battery in the laptop. When new, most laptops are equipped with batteries that have about 50 Watt-hours of capacity. Since laptops draw 10-12 Watts per hour, about 4-5 hours is the most you can expect the batteries to last before recharge is required.
That is the situation IF they are new. Since the design of the battery systems in laptops typically charge to 100% and discharge to 0%, the battery begins to lose capacity after a few hundred charging cycles. It is possible that many laptops in use have degraded batteries with 40 or fewer Watt-hours of capacity.
Battery Power Solutions are not Created Equal
You could do a search online and find many battery systems that purport to be supplemental power with USB-C connections.
Akin to something you could buy at the airport gift shop, most designs pay little attention to sustainability, durability, or longevity. Some even advertise “Lithium-ion” the magic marketing words in a battery description. The capacity may be limited to just a few hours of laptop operation. This is not enough for a day in a classroom. And it explains the reason for the low price.
They may also express their battery life in mAh, or Milliamp Hours. While this is technically correct from an engineering perspective, it does little to inform you unless you learn to do the math.
Lithium-ion batteries last longer if charged slowly (as in “overnight”) to 90% of the battery’s capacity and discharged to 10% of the capacity. Most of the low-price solutions do not incorporate this feature. Battery life could be as little as 18-24 months.
A low price is not necessarily a low cost.
August Berres has a Better Answer
Our portable battery systems provide 200 Watt-hours of power through two USB-C connections. While laptops vary in power consumption, assume 12 Watts per hour (not atypical). So, one of our battery systems will last more than 16 hours. This will enable two students to power laptops for an entire day from one battery! This is half the number of battery and charging systems required in a classroom.
Batteries are better than outlets in a classroom. Most students will have adequately charged laptops. You do not need 120V outlets at every seat. Supplemental power is only required where it is needed.
Are they safe? Yes, our control systems detect both over-current and over-temperature. When these conditions occur, our batteries shut down and will not restart until the anomaly is ended. We believe this is an essential feature in a classroom environment.
Are they durable? Unlike the lower-cost materials in other products, our carry cases are made from polycarbonate. They stand up to the rigors of everyday use. We cannot promise anything about abuse, however. That is more a discipline issue than a product design issue. Lithium-ion batteries must be treated with respect.
How long do they last? We control the charging rate to extend product life. We charge up to 90% and discharge down to 10%. We can fully charge overnight. With this regimen, the batteries will retain at least 80% of their capacity after 2,500 cycles. If each battery is cycled once per day for 250 days, the calculated life is reasonably 10 years.
How are they charged? August Berres also has the most solutions for battery charging in the industry. Charge 3, 12, or 24 batteries simultaneously from a single 120V outlet.
“Let’s not let technology get in the way of learning. Let’s use it to enhance learning.”
